NAME
App::Inotify::Hookable - blocking command-line interface to inotify
SYNOPSIS
Watch a directory, tell us when things change in it:
inotify-hookable --watch-directories /tmp/watch-this
Watch a git tree, some configs, and a repository of static assets,
restart the webserver or compress those assets if anything changes:
inotify-hookable \
--watch-directories /etc/uwsgi \
--watch-directories /git_tree/central \
--watch-directories /etc/app-config \
--watch-directories /git_tree/static_assets \
--on-modify-path-command "^(/etc/uwsgi|/git_tree/central|/etc/app-config)=sudo /etc/init.d/uwsgi restart" \
--on-modify-path-command "^/git_tree/static_assets=(cd /git_tree/static_assets && compress_static_assets)"
Or watch specific files:
inotify-hookable \
--watch-files /var/www/cgi-bin/mod_perl_handler \
--on-modify-command "apachectl restart"
DESCRIPTION
This simple command-line program is my replacement for the functionality
offered by Plack's Filesys::Notify::Simple. I found that on very large
git trees Plack would spend an inordinate amount watching the filesystem
for changes.
This program uses Linux::Inotify2, so the kernel will notify it
instantly when something changes (actually it's so fast that we have to
work around how fast it sends us events).
The result is that you can run this e.g. in a screen session and have it
watch your development environment, and your webserver will have begun
restarting before your finger leaves the *save* button.
vim and emacs temporary files are ignored by default (see
"--ignore-paths".) so you can edit your files without your server
restarting unnecessarily.
Currently the command-line interface for this is the only one that
really makes sense, this module is entirely blocking (although it could
probably run in another process via POE or something). Patches welcome.
OPTIONS
"-w" or "--watch-directories"
Specify this to watch a directory, you can give this however many times
you like to watch lots of directories.
"-f" or "--watch-files"
Watch a file, specify multiple times for multiple files. You can watch
files and directories in the same command.
"-r" or "--recursive"
If you supply this any directory you give will be recursively watched.
This is on by default.
"-c" or "--on-modify-command"
A command that will be run when something is modified.
"-C" or "--on-modify-path-command"
A key-value pair where the key is a regex that'll be matched against a
modified path, and the value is a command that'll be run. See the
"SYNOPSIS" for an example.
Useful for e.g. restarting a webserver if you modify directory A but
compressing some static assets if you modify directory B.
"-t" or "--buffer-time"
Linux will send you inotify events really fast, so fast that if you run
something like:
touch foo bar
You might get an event for foo in one batch, followed by an event for
bar later on.
To deal with this we enter a loop when we start getting events and sleep
for a default of 100 microseconds, as long as we keep getting events we
keep sleeping for 100 microseconds, but as soon as we haven't received
anything new we fire off our event handlers.
"-i" or "--ignore-paths"
Regexes for files/directories to ignore events for. By default this is
set to regexes for vim and emacs temporary files, "qr{\..*sw.\z}" and
"qr{\.\#[^/]+\z}" respectively.
The regexes match after any "/" in the path or the beginning of the
string.
"-d" or "--debug"
Spew out some verbose debug output while running.
ACKNOWLEDGMENT
This module was originally developed at and for Booking.com. With
approval from Booking.com, this module was generalized and put on CPAN,
for which the authors would like to express their gratitude.
AUTHOR
Ævar Arnfjörð Bjarmason